The present invention relates to a high-voltage cable joint for connecting terminus of conductors of a first and a second power cable, the conductor of each cable being surrounded by, successively, a first insulation layer, a semi-conductive layer, a metallic screen and a second insulation layer, said cable joint including a junction body comprising connection means for connecting together bared parts of the terminus of said conductors and insulation means surrounding, from a first end to a second end thereof, bared parts of the semi-conductive layer, of the first insulation layer and of the conductor of said first power cable, said connection means, and bared parts of the conductor, of the first insulation layer and of the semi-conductive layer of said second power cable, the metallic screen of said first power cable being electrically connected to a first end of a first metallic tubular shielding member that covers said junction body and has a second end overhanging beyond the second end of the junction body, an insulation sleeve being provided between said junction body and said first shielding member, said insulation sleeve also having an end overhanging beyond said second end of the junction body, and the metallic screen of said second power cable being electrically connected to a second end of a second metallic tubular shielding member that has a first end abutting against said second end of said junction body, said first end of said second shielding member being partially engaged underneath the hanging end of said insulation sleeve as well as under the second end of said first shielding member without having an electrical contact therewith.
Such a cable joint is already known in the art, e.g. from "Cross-bonding joint 123kV" type MP1. 123-31/32 of "CORTAILLOD COSSONAY CABLE".In this known cable joint, a pre-insulated rigid metallic tube is used as first tubular shielding member for covering the whole junction body. A first end of the rigid tube is soldered to the metallic screen of the first power cable, whilst at the other end of the cable joint, a relatively big epoxy insulator surrounds the second power cable and is partially engaged into the second end of the metallic tube. The epoxy insulator has embedded two conductors electrically separated from each other and connected to distinct terminals. One terminal is electrically connected to the metallic tube, whilst the other terminal is soldered to the metallic screen of the second power cable. The embedded conductors extend out from the epoxy insulator, diametrically opposed, at a same end of the cable joint where earthing connection and/or cross-bonding is then possible.
Normally, all the layers of the two power cables should be continued through the cable junction. They are therefore re-constructed one after the other. For instance, the terminus of the conductors are interconnected by the connection means, the insulation layers are continued through the junction body, the metallic screens, that also have an important watertightness shielding role, are continued through the tubular shielding members, etc. . . . It is however to be noted that the electrical contact between the metallic screens of the power cables is preferably interrupted at a so-called "shield-break" and that each metallic screen is electrically accessible from outside the cable joint. The reason therefore is to allow the well known cross-bonding. Cross-bonding may for instance be necessary in multi-phase, e.g. three-phase, cable installation where the currents that are induced in the metallic screens of the power cables can become intolerably high. These currents can then be eliminated by dividing the screens into isolated sections that are cross-interconnected between the power cables of different phases.
In the known cable joint, the interrupted shielding layer or shield-break is made water impervious owing to the epoxy insulator. However, the weight of the casing and of such an epoxy insulator is relatively high. As a consequence, it is relatively difficult to handle the parts of this known cable joint. This cable joint is further also relatively expensive because of the materials used therein.